Cathode ray scanning device



Oct. 9, 1934.

w. ILBERG C ATHODE RAY SCANNING DEVICE Filed lay 21, 1931 Mil/flitulk-*1 I II IIIII INVENTOR W/ILDHMP M6506 ATTORNEY Patented Oct. 9, 1934CATHODE an SCANNING DEVICE Waldemar Ilberg, Berlin, Germany, assignor toTelefunken Gesellschaft fiir Drahtlose Telegraphic to. b. 11., Berlin,Germany, a corporation of Germany Application May 21, 1931, Serial No.538,327

In Germany May 23, 1930 i 47 Claims.

The use of a Braun cathode ray tube at the receiving end of a televisiontransmission system to act as a picture-point or unit distributer isknown in the art. In most cases deflection of the cathode 'ray penciloccurring by lines is accomplished by supplying the four deflectorelectrodes with two suitable alternating current potentials producedeither locally or transmitted from the transmitting end. Contradistinct'to this mode of operation, in the invention hereinafter to be disclosedonly one alternating current potential serves for coordinate control, orto be more precise, the potential which occasions.

movement of the cathode rays along a line, whereas the return of the raypencil to the beginning of the next line and also return to thebeginning of the first line after completion of the last line is insuredby the cathode ray pencil itself.

With this end in view, auxiliary electrodes are disposed according tothis invention upon the fluorescent screen or in the neighborhoodthereof. The cathode ray pencil is caused to impinge upon theseelectrodes after the line motion has been terminated so that, in amanner which will hereinafter become apparent, the restoration or returnof the cathode ray pencil to the beginning of the next line isoccasioned.

One embodiment of the invention is shown by way of diagrammaticrepresentation in the accompanying drawing.

The cathode ray pencil is furnished from the cathode 1, and it issuesfrom the diaphragm 3 of the anode member 5 which is raised to a suitablepotential by the potential source 7. When so directed the cathode ray isin the form of a parallel pencil or beam. In order to deflect thecathode ray pencil 9 in the direction of the lines 11 traced upon thefluorescent screen 13 forming 40 the end wall, being adjacent to the endwall of the cathode ray tube 15, a pair of deflecting plates 1'7 and 19are provided. Upon these plates, as will hereinafter appear, aconvenient alternating current potential is applied.

Referring to the drawing the assumption has been made that thiscontrolling alternating current potential is obtained from anintermittence circuit arrangement comprising a source of current 21, aresistance 23 and a condenser 25 with a parallel-connectedgaseous-conduction lamp 2'7.

As will now appear, the cathode ray pencil 9 as accelerated by the anode5 is caused to fall upon the fluorescent screen 13 and is caused tosweep the screen in a transverse direction by 55 the potentials appliedto plates 17 and 19. After the termination of a line 11 of transversescanning, the cathode ray pencil is caused to impinge briefly upon anelectrode element 29. This electrode is connected by way of a variableresistance 31 with a condenser 33 whose potential, during each suchcontact, is increased by the same amount. In parallel relationship tothis condenser element 33 the second pair of deflector plates 35 and 37,for controlling the vertical movement of the cathode ray, are connected.The potential difference upon the plates 35 and 3'7 which is suddenlyraised after completion of each transverse scanning line of the cathoderay as influencing the charge on condenser 33 causes the next succeed gtransverse scanning line to be shifted a suitable amount vertically withreference to the preceding line.

At the end of the last transverse scanning line 11, no further contactis made with electrode 29, and the cathode ray pencil, after havingscanned the screen 13, impinges upon the electrode element 39.

This contacting of the ray 9 upon electrode 39 results in completedischarge of condenser 33, and, by virtue of the dependence of thepotential of plates 35 and 37 for producing vertical deflection upon thecharge on condenser 33, the discharging of condenser 33 returns theluminous spot produced upon screen 13 through impact of the cathode ray15 to the beginning of the picture. By the embodiment illustrated on thedrawing, the discharge of capacity 33 is effected by a relay 41 which isenergized by the cathode ray pencil impinging upon the electrode 39 andwhich then causes the condenser to be short-circuited, for example, byclosing armature 43 upon contacts 45, 4'7 which are connected throughsuitable conductors to either side of condenser 33.

In lieu of the relay 41 a glow discharge or gaseous-conduction tubeconnected in parallel relation to the condenser 33 may be used, in amanner similar to that assumed for the transverse control, which tubeafter attaining a certain potential difference is ignited after eachpassage or scanning of the picture surface whereby the starting value ofthe potential for the initial position of the cathode ray pencil isrestored. With such a control for the vertical movement of the raypencil 15, the electrode element 39 may be dispensed with, since theglow discharge lamp will flash through the accumulation of chargesthereon. I

As the invention has been explained above, no reference has been made tothe production of any varying intensities of illumination which wouldappear upon the fluorescent screen 13.

; However, in order to produce an electro-optical image of a subjectlocated at a point of transmission, it is desirable to control theintensity of ties of light and shadow for successive elemental areas ofthe subject are received upon an antenna system 49, or, where desired,may be received over a wire line, and are then transferred to thereceiver amplifier 51. Connected with the output of the receiveramplifier 51 are two conductors 53 and 55, of which conductor 53connects with a grid element 5'7 contained within the tube 15 and theconductor 55 connects with the electrode element 1 serving as a sourceof cathode rays. The emitting electrode 1 is suitably heated by means ofa current source 59, and this heating may be controlled where desired bymeans of a resistor element 61. As was taught by United States Patent toNicolson #1,470,696, October 16, 1923, a grid element may be providedfor controlling the intensity of the cathode rays as they sweep acrossthe fluorescent screen, and the arrangement herein shown is illustratedas embodying the grid intensity control principle disclosed by Nicolson.It is, however, within the scope of my invention to use also other formsof control of intensity of the cathode ray, and these may be, forexample, of the type disclosed by British Patent #27570 of 1907, whereinthe cathode ray streamis deflected acrossadiaphragm so as tocut off aportion of the stream and thus reduce the area effective upon thefluorescent screen, or, where desired, the intensity control may be inaccordance with the disclosure in United States Patent #1,16l,734, Nov.23, 1915, wherein a method of controlling the intensity of lightproduced upon the fluorescent screen is in accordance with the timeperiod during which the ray is permitted to impinge upon each successiveelemental area of the fluorescent screen.

Several modifications of the control are, of course, possible, and sincethe invention is not directed to the intensity control per se, furtherreference to this form of arrangement is not believed to be necessary,although it willbe appreciated that it is fully within the scope of theinvention to resort to other types of intensity control systems wherethese are found suitable.

While the invention has been illustrated with an electrostatic means fordeflecting the in tensity controlled cathode ray stream, it is alsowithin the scope of the invention to substitute for .the electrostaticdeflecting means electromagnetic deflecting means, or to substituteelectromagnetic deflecting means for one of the electrostatic deflectingmeans and then retain one electrostatic deflecting means. In the eventthat the last named system is used, then it is preferable to retainelectrostatic deflecting means for the fast motion of the cathode raystream and to substitute electromagnetic means for deflecting the streamalong its slower moving path.

Having now described my invention in one of its preferred embodiments,it is, of course, ob-

vious that many modifications and changes may be made therein withoutdeparting from its spirit and scope, and I, therefore, believe myself tobe entitledtomakeanduseanyandallofthese modifications such as suggestthemselves to those skilled in the art to which the invention relatesprovided such changes and modifications fall fairly within the spiritand scope of the hereinafter appended claims, wherein I claim:

1. In a cathode ray system, means for developing a cathode ray andmoving the said ray across a predetermined path, and means operable fromsaid ray at predetermined points in the motion thereof for producing amotion thereof along a path transverse to said flrst named path.

2. A cathode, ray device comprising a source for generating cathoderays, means for deflecting said generated rays in one plane, and meansoperable from the cathode ray pencil for producing a deflection thereofin a second plane.

3. A scanning system comprising a source for generating cathode rays,means for deflecting said rays back and forth across a screen in onepath, and means controlled by the cathode ray in its movement along saidpath of deflection for causing a deflection thereof along a path bearingan angular relationship to said first named path of deflection forcausing the flrst named deflection to produce jointly with said seconddeflection a series of substantially parallel paths across the screen.

4. A scanning system comprising a source for generating cathode rays,means for deflecting said rays in a horizontal direction, and meanscontrolled by the cathode ray in its movement in said horizontaldirection of deflection for causing a deflection thereof along avertical path during the time period of the repeated horizontaldeflections so as to cause said ray to trace a series of spacedhorizontal traversals.

5. A scanning system comprising a source for generating cathode rays, anelectrostatic field for deflecting said rays to trace a path across arecording screen in one direction, and means controlled by the cathoderay once during each movement thereof along said path of deflection forcausing each successive deflection thereof along said first .directionalpath to be spaced apart from the preceding path by a predeterminedamount.

6. A scanning system comprising a source for generating cathode rays, anelectrostatic fleld'for deflecting said rays back and forth along aseries of paths extending in a transverse direction to a plane ofviewing, and means controlled by the cathode ray in its back and forthmotion along said path for progressively deflecting the said ray at thecompletion of each first named path along a second series of pathsextending transverse to said first paths, and upon completion of apredetermined number of changes of path along said second line ofdeflection retuming the path of said flrst deflection to the lineoriginally traced.

'7. In a television system, a scanning device comprising a cathode raytube having a source for generating cathode rays and a screenrespon'sive to the action of said rays, means for deflecting saidcathode rays along a path transverse of the screen in one-direction, andmeans operable by said cathode ray at time periods when said cathode rayhas been deflected to a maximum extent in said direction formoving thesaid ray vertically so as to trace each succeeding path with apredetermined'spacing with source for generating cathode rays and aviewing screen responsive to said rays, means for sweeping said cathoderays back and forth across said screen in a first path, and meansoperable by said cathode ray at one extreme position in the motionthereof for producing a progressive change in the/position at which thesaid ray sweeps said screen for causing the said screen to be subjectedto said rays along a series of paths parallel to each other and spacedapart from each other with a predetermined spacing.

9. A television system comprising a cathode ray receiving device, asource of cathode rays, a fluorescent screen upon which said cathoderays are adapted to impinge so as to produce luminous efiects thereon,means for deflecting said cathode rays along a path extending across'said screen in one direction, and means associated with said screen andresponsive to the cathode ray stream once during each period ofdeflection along one of said paths for producing a deflection in asecond direction bearing an angular relationship to said first nameddirection for causing successive paths of deflection along said firstdirection to be spaced apart from and adjacent to each preceding pathfor a predetermined number of deflections along said first path.

10. A television receiving device comprising a cathode ray tube having asource for generating cathode rays and a fluorescent screen adapted tobecome luminescent upon bombardment of said cathode rays, an electrodeadjacent said fluorescent screen and extending along one edge thereof,means for deflecting said cathode rays transversely of said fluorescentscreen in one path and causing said rays to impinge upon said electrodeat the end of each transverse motion thereof, and means operable at timeperiods when said cathode ray impinges upon said electrode for movingsaid ray in a direction substantially perpendicular to said first namedpath of deflection for causing each successive traversal of said cathoderay to trace a path substantially parallel and spaced apart from saidfirst named path.

11. In a television system comprising a cathode ray receiving devicehaving a source for producing a pencil of cathode rays, a fluorescentscreen upon which said cathode rays are adapted to impinge so as toproduce luminous efiects thereon, means for causing said cathode rays totrace a series of points back and forth across said screen, meansassociated with said screen and responsive to the cathode ray streamonce during each back and forth motion thereof for deflecting the saidray and causing the succeeding series of points to be displaced in adirection substantially perpendicular to the path of said first namedseries of points by a predetermined amount, and means operable from saidray at time'periods when a predetermined number of deflectionsperpendicular to the first series of points have been produced forcausing a complete recurrence of all of said series of points inidentical order.

12. A television receiving device comprising a cathode ray tube having asource for generating cathode rays, a fluorescent screen adapted tobecome luminescent upon bombardment of said cathode rays, an electrodeadjacent said fluorescent screen and extending along one edge thereof,means for deflecting said cathode rays transversely of said fluorescentscreen along a predetermned path in one direction and causing said raysto impinge upon said electrode at the end of each transverse motionthereof, a capacity means having the charge thereon progressively increased at each time period when said cathode ray impinges upon saidelectrode for moving said ray in a direction substantially perpendicularto said first named path of deflection for causing each successivetraversal of said cathode ray to trace a path substantially parallel andspaced apart from said first named path, and means operable from saidray upon a completion of a predetermined number of traversalsof saidscreen in said first direction for discharging said capacity and causinga complete and similar repetition of each of said paths of deflection.

13. In an electro-optical image producing system, a source of cathoderays, a screen adapted to become luminescent upon bombardment of saidcathode rays, means for moving said cathode rays across said screen inone direction, an

electrode element arranged adjacent said screen and adapted to besubjected to said cathode rays upon each motion of the cathode rayacross said screen, and means operable from said electrode as controlledby the impact of said cathode ray stream thereon for causing aprogressive movement of said cathode ray across said screen in adirection substantially transverse to said first named direction ofmotion of said ray.

14. In an electro-optical image producing system having a source ofcathode rays, a screen adapted to become luminescent upon bombardment ofsaid cathode rays, means for moving said cathode rays across said screenin one direction, an electrode element arranged adjacent said screen andadapted to be subjected to said cathode rays upon each motion of thecathode ray across said screen, means operable from said electrode ascontrolled by the impact of said cathode ray stream thereon for causinga progressive movement of said-cathode ray across said screen in adirection substantially transverse to said first named direction ofmotion of said ray, and means operable from said ray upon completion ofa predetermined series of said progressive deflections for producing adeflection in the direction opposite said deflection produced by saidray and of an amount equal to the sum of all of said progressivedeflections so as to permit a complete repetition of all of saiddeflections in a like order of recurrence.

15. In a television viewing device, a source of cathode rays, afluorescent screen adapted to become luminescent upon bombardmentthereof by said cathode rays, means for deflecting said rays in theirpath of motion toward said screen so as to cause said rays to trace apath transverse to said screen in one direction, an electrode extendingalong the edge of said screen perpendicular to the path traced acrosssaid screen by said rays and adapted to be influenced by said ray onceduring each transverse moton of said ray across said screen, meansoperable from said electrode as influenced by the said cathode rayimpinging thereon for deflecting said ray in a direction substantiallyperpendicular to said first named deflection path for causing saidcathode ray to sweep across said screen along successive parallel paths,and a second electrode adjacent said screen and adapted to be influencedby said cathode ray during a single motion only thereof across saidscreen for changing the deflection path of said ray in said seconddirection from a maximum to a minimum upon the completion of a series oftraversals of said ray across said screen in said first named direction.

16. The method of television scanning with a cathode ray device whichcomprises developing a cathode ray, moving the said ray across apredetermined path, and producing from the cathode ray at predeterminedpoints in the motion thereof along said path a motion thereof along asecond path transverse to said first named path.

17. The method of television scanning comprising generating cathoderays, deflecting said generated rays in one direction, and producingfrom the cathode ray pencil a deflection thereof in a transversedirection at predetermined points in the deflection in said firstdirection.

18. A cathode ray device comprising a source for generating a cathoderay pencil, means for deflecting the generated cathode ray pencil in oneplane, and meansoperative from the cathode ray pencil for producing aprogressive deflection of the cathode ray pencil along a series ofplanes spaced apart from and parallel to said first plane of deflection.s

19. In a cathode ray system, means for developing a cathode ray, meansfor moving the said ray across a predetermined path, means operativefrom said cathode ray at predetermined points in the motion thereof forproducing a motion thereof along a path transverse to said first namedpath, and means operable during the motion of the cathode ray across thefirst predetermined path for varying the effective intensity of thedeveloped ray.

20. A cathode ray device comprising a source for generating cathoderays, means for project ing the generated rays toward a fluorescentscreen formed as a part of the cathode ray device, means for deflectingthe generated cathode rays in one plane, means operative from thecathode ray for producing a deflection thereof ina second plane,

and means operable during the motion of the cathode ray in the firstplane for varying the effective intensity of the ray impinging upon thefluorescent screen.

21. A scanning system comprising a source for generating cathode rays,means for deflecting the cathode rays along a predetermined path backand forth across a fluorescent screen in such manner that the rate oftraversal in one direction is slow and in the other direction rapid,means controlled by the cathode ray during its deflection back and forthacross the screen for causing a deflection thereof in a directionparallel to and spaced apart from the preceding path so as to producejointly with the first deflection a series of parallel paths across thescreen, and means operable during the motion of said cathode, ray acrossthe first predetermined path for varying the effective intensity of thedeveloped ray impinging upon the screen.

22. A scanning system comprising a source for generating cathode rays,means for deflecting the generated rays in a horizontal direction, meanscontrolled by the cathode ray in its movement along the horizontal pathof deflection for cars-- ing a deflection thereof along a vertical pathduring the time period of the repeated horizontal deflections so as tocause the generated ray to trace a series of spaced horizontal pathsfandmeans operable during the motion of the ray across each horizontal pathfor varying the intensity of the developed ray.

23. A scanning system comprising a source for generating a cathode raypencil, an electrostatic field for deflecting the cathode ray pencil totrace a path across a recording screen in one direction, meanscontrolled by the cathode ray once during each movement thereof alongthe I path of deflection for causing each successive deflection thereofalong the, first directional path to be spaced apart from the precedingpath by a predetermined amount, and means for controlling the effectiveintensity of the generated cathode ray pencil upon the screen during theperiods of traversal.

24. In a television system, a scanning device comprising a cathode raytube having a, source for generating a cathode ray pencil and a screenresponsive to. the action of the cathode ray pencil, means fordeflecting the cathode ray pencil along a path transverse to the screenin one direction, means operative by the cathode ray pencil at timeperiods when the cathode ray has been deflected to a maximum extent inone direc tionfor moving the cathode ray in a direction transverse tothe first direction of motion so as to trace each succeeding path ofdeflection with a predetermined spacing with respect to the precedingpath, and means to vary the observable intensity of the responseproduced upon the screen by the traversal of the cathode ray streamflecting the ray and causing the succeeding series of points to bedisplaced in a direction-substantially perpendicular to the path of thefirst named series of points by a predetermined amount, means operativefrom the ray at time periods when a predetermined number of deflectionsalong the perpendicular path have beenproduced for causing a completerecurrence of all of the paths in identical order, and means operable tocontrol the effective intensity of the response produced upon thefluorescent screen by the cathode rays during the back and forth motionthereof across the screen.

26. A television receiving device comprising a cathode ray tube having.a source for generating cathode rays, a fluorescent screen adapted tobecome luminescent upon bombardment of the cathode rays, an electrodeadjacent the fluorescent screen and extending along one edge thereof,means for deflecting the cathode rays transversely of the fluorescentscreen along one predetermined path of deflection and to impinge uponthe electrode at the end of each transverse motion thereof, a capacitymeans having the charge thereon progressively increased at each timeperiod when the cathode ray impinges upon the electrode for moving theray in a direction substantially perpendicular to the first named pathof deflection for causing each successive traversal of the cathode rayto trace a path substantially parallel and spaced apart from the firstnamed path, means operative from the ray upon a completion of apredetermined number of traversals of the screen in the first directionfor discharging the capacity and causing a complete and similarrepetition of each of the paths of deflection, and

a controlling element within the tube for controlling the luminousresponse produced upon the fluorescent screen by the traversal of thecathode rays.

27. In an electro-optical image producing system, a source of cathoderays, a screen adapted to become luminescent upon bombardment of thecathode rays, means for moving the cathode rays across the screen in onedirection, an electrode element arranged adjacent the screen and adaptedto be subjected to the cathode rays upon each motion of the cathode rayacross the screen, means operative from the electrode as controlled bythe impact of the cathode ray stream thereon for causing a progressivemovement of the oathode ray across the screen in a directionsubstantially transverse .to the first named direction of motion of theray, and means operable during the motion of the cathode ray in thefirst direction for varying the luminous intensity observable from thebombardment of the rays.

28. In a television viewing device, a source of cathode rays, afluorescent screen adapted to become luminescent upon bombardmentthereof by the cathode rays, meansfor deflecting the rays in their pathof motion toward the screen so as to cause the rays to trace a pathtransverse to the screen in one direction, an electrode extending alongthe edge of the screen perpendicular to the path traced across thescreen by the rays and adapted to be influenced by the ray once duringeach transverse motion of the ray across the screen, means operativefrom the electrode as influenced by the cathode ray impinging thereonfor deflecting the ray in a direction substantially perpendicular to thefirst named deflection path for causing the cathode ray to sweep acrossthe screen along successive parallel paths, a second electrode adjacentthe screen and adapted to be influenced by the cathode ray during asingle motion only thereof across the screen for changing the deflectionpath of the ray in the second direction from a maximum to a minimum uponthe completion of a series of traversals of the ray across the screen inthe first named direction, and a means for varying the intensity of theluminous effects produced by the bombardment of said cathode rays.

29. The method of controlling a cathode ray tube system which comprisesdeveloping a cathode ray, moving the developed ray to cause it to trav-I erse a predetermined path, and producing from the ray at predeterminedpoints in the motion thereof along the traversed path a motion along apath transverse to said first named path.

30. The method o operating a cathode ray device which comprisesgenerating cathode rays, deflecting the generated rays in one plane, and

producing from the cathode ray at one point in its deflection a seconddeflection along a path in a diflerent direction from the first plane ofdeflection.

31. The method of scanning the screen of a cathode ray tube whichcomprises generating cathode rays, deflecting the generated rays backand forth across the screen along one predetermined path, andcontrolling by the cathode ray in its back and forth movement along thepath of deflection a second deflection of the ray along a path bearingan angular relationship tmthe first path of deflection, so that thefirst deflection path produces jointly with the second deflection path aseries of substantially parallel paths across the screen.

32. The method of scanning the screen of a cathode ray tube whichcomprises generating cathode'rays, deflecting the generated rays backand forth across the screen along one predetermined path, controlling bythe cathode ray in its back and forth movement along the path ofvdeflection a second deflection of the ray along a path bearing anangular relationship to the first path of deflection, so thatthe firstdeflection path produces jointly with the second deflection path aseries of substantially parallel paths across the screen, andcontrolling the intensity of the oathode rays impinging upon the screenfor varying the intensity of the luminous efiects produced.

33. The method of controlling a cathode ray tube system which comprisesdeveloping a cathode ray, movingthe developed ray to cause it totraverse a predetermined path in two directions wherein the motion inone direction is slow and in the other direction rapid, producing fromthe cathode ray at a predetermined point in the motion thereof along thetraversed path a motion along a path transverse to the first path, andcontrolling the intensity of the cathode ray in its motion along thetraversed paths to vary in proportion to the intensity controlling theluminous eflects produced. i

34. The method of scanning the fluorescent end wall of a cathode raydevice which comprises generating a cathode ray stream; generating anelectric field for deflecting the ray stream to trace a path acrossgthescreen in one direction, and controlling by the ray once during eachmovement thereof along the path of deflection a second deflection of theray to produce a traversal path parallel to the first directional pathand spaced apart therefrom by a predetermined separation.

35. The method of scanning the fluorescent end wall of a cathode raydevice which comprises generating a cathode ray stream, generating anelectric field for deflecting the ray stream to trace a path across thescreen in one direction, controlling by the ray once during eachmovement thereof along the path of deflection a second deflection of theray to produce a traversal path parallel to the first directional pathand spaced apart therefrom by a predetermined separation, andcontrolling during the deflection along the first path a change in theintensity of the cathode rays to produce variations in the intensity ofthe luminous efi'ects. produced thereby.

36. The method of scanning a viewing screen with a cathode ray devicefor television and the i like comprising generating cathode rays andprojecting the generated rays toward a viewing screen responsivethereto, sweeping the generated cathode ray back and forth across thescreen along a predetermined path, and producing by the cathode ray atthe extreme position of the motion thereof in one direction aprogressive change in the position at which the screen is sequentiallysubjected to the influence of the generated cathode ray so that thescreen is traversed along a series of paths parallel to each other andspaced apart from each other with a predetermined spacing.

37. The method of controlling the position of electro-opt'ical images ina cathode ray television system which comprises producing a pencil ofcathode rays, projecting the rays upon the fluorescent screen of thesystem to produce luminous effects thereon, causing the cathode rays totrace a series of light points back and forth across the screen,deflecting the cathode ray and causing the succeeding series of lightpoints to be displaced in a direction substantially perpendicular to thepath of the first named series of light points by a predetermined amountin accordance with the response of the cathode ray stream upon thescreen once during each back and forth motion ,thereof, and producingfrom the ray at time periods when a predetermined number of deflectionsalong a perpendicular path have been produced a complete recurrence ofall of the said paths in identical order.

38. The method of controlling in a cathode ray tube the points at whicha cathode ray stream generated therein impinges upon a predeterminedtransverse section in the path oi. the generated ray which comprisesdeflecting the ray to cause a traversal thereby of the predeterminedsection and utilizing the cathode ray to cause successive traversals ofthe predetermined section to bev spaced one from the other. 7

39. The method of controlling in a cathode ray tube the points at whicha cathode ray'stream generated therein impinges upon a predeterminedtransverse section in the path of the generated ray which comprisesdeflecting the rag to cause a traversal thereby of the predeterminedsection and utilizing the cathode ray to cause successive traversals ofthe predetermined section to be spaced apart from and parallel to eachother.

40. The method of operating a cathode ray device which comprisesgenerating a cathode ray pencil,normally causing the cathode ray pencilto be deflected in such manner as to travel back and forth across apre-established path on a predetermined surface and spacing eachsuccessive path across the surface by the action of the ray in itsprevious sweep-path across the surface.

41. The method of operating a cathode ray device which comprisesgenerating a cathode ray pencil, normally causing the cathode ray pencilto be deflected in such manner as to travel back and forth across apro-established path on a predetermined surface, spacing each successivepath across the surface by the action of the ray in its previous sweeppath across the surface and causing by the ray pencil a repetition ofthe entire series of back and forth traversals of the surface atpredetermined periods.

42. In a cathode ray device, means for generating a cathode ray, aconducting surface upon which the generated ray'is adapted to impinge,

anelectrode element adjacent the conducting surface,.means to deflectthe generated ray in such manner as to cause the ray to traverse theconducting surface and the adjacent electrode at a relatively slowtraversal speed and then to traverse the same elements in reverse orderat a relatively high speed, and means controlled by the electrodeadjacent the conducting surface for controlling the position on theconducting surface at which each subsequent ray traversal takes place.

43. A scanning device comprising a cathode ray tube including means forgenerating therein a cathode ray stream, means to produce sawtoothformation electrical impulses to deflect the cathode ray stream to causenormally a continual traversal and re-traversal ofa surface along apredetermined path by the ray and means provided by the cathode raystream for producing saw-tooth formation electrical impulses to deflectat each traversal the cathode ray stream in a direction transverse tothe first deflection.

44. In a cathode ray device, means for gen erating a cathode ray, asurface upon which the generated ray is adapted to impinge, an electrodeelement adjacent the surface, means to deflect the generated ray in suchmanner as to cause the ray to traverse the surface and the adjacentelectrode along a predetermined path in one direc tion at a relativelyslow traversal speed and then to traverse the same elements in reverseorder at a relatively high speed, and means for producing from theimpact of the cathode ray upon the electrode adjacent the surface acontrolling voltage to control the location of each subsequent path oftraversal of the surface by the cathode ray.

45. In a cathode ray device, means to develop a cathode ray, meanstogenerate saw-tooth f onnation electrical impulses for moving the rayin one plane, and means controlled by the generated cathode ray forgenerating saw-tooth formation electrical impulses for moving the ray ina second plane.

:16. In a television system, a scanning, device,

comprising a cathode ray tube having a source for generating a cathoderay pencil and a screen re-.

sponsive to the action of the cathode ray pencil, means for deflectingthe cathode ray pencil along a' path transverse to the screen in onedirection, means operative by the cathode ray pencil at time periodswhen the cathode ray has been deflected to a maximum extent in onedirection for moving the cathode ray in a direction transverse to thefirst direction of motion so as to trace each succeeding path ofdeflection with a predetermined spacing with respect to the precedingpath.

47. In a cathode ray device having means to generate a. cathode raystream, means for causing the cathode ray stream to traverse a path backand "forth across a predetermined surface in the path of the generatedcathode ray stream, an electrode positioned adjacent the surface acrosswhich the ray is moved, means controlled by the cathode ray streamimpinging upon the electrode upon each traversal of the surface to causethe succeeding traversal of the surface by WALDEMAR ILBERG.

